Abstract: Aiming at the problem of diesel and gasoline mixture in batch transportation, experiments are carried out on the mixture of diesel and gasoline from a refinery. Considering the influence of quality allowance of different products and quality potential, maximum allowable proportion of the mixture is determined. The comparison of the test results to that of the empirical formula and data analysis demonstrate that different products has different mixing proportions, and the empirical formula applied to the contamination cut and/ or treatment can be utilized with caution. Meanwhile, a forecast model for process index of quality control of the mixed products is given in allusion to the limitation of empirical equation.